Like broiler farms, large integrated layer farms are concentrated mostly in the central
region, although layer farms are distributed more evenly across regions. As almost all egg
products are sold domestically, the industry was not, in the past, subject to such stringent
requirements as the broiler industry. Although the HPAI epidemic has changed this somewhat
over the past few years, structural changes are coming much more slowly to the layer
industry than to the broiler industry. For example, there have been strong – and apparently
quite reliable – rumours that a significant number of layer farms are using the HPAI vaccine,
even though the HPAI vaccine has never been approved (in fact it has always been banned)
by the Thai government.